Signal generator



Sept. 20, 1949.

Filed Sept. 9, 1944 W. R. FLATFORD S IGNAL GENERATOR 4 Sheets-Sheet rl Sept. 20, 1949. w. R. FLATFORD SIGNAL GENERATOR 4 Sheets-Smet 2 n Filed Sept. 9, 1944 Fmi-6 0 w ----M, 8 2 f, m. I m .IIT a is, 7 0 a ML 2M@ 2 3 liv..

0u y. u l f L@ v s 4 I8 M8 .IlIl-vlvl dlg INVENTOR Sept. 20, 1949. w. R. FLATFORD S IGNAL GENERATOR 4 Shee'ts-Sheet 3 Filed sept. 9, 1944 RFQ OT.. E 3 m lo@ ma. m

Sept. 20, 1949. w. R. FLATFQRD SIGNAL GENERATOR 4 Sheets-Sheet 4 Filed Sept. 9, 1944 "matassa zo, i949 i UNITED. STATESi wirr-:NTA ori-Ica SIGNAL GENERATOR William R. vFlatl'orcl, Bartlesville, 0kla.,.asdnor to Phillips Petroleum Company, a corporation Application September 9, 1944, vSerial No.4 553,337

` Y 4 Claims. (Cl. F15-373) This invention relates to signal generators of a type especially adapted for use in the electrical logging of oil wells and the like while drilling. and is further of the typewhich is a self-contained source of suitable signal current which can be lowered into the bore hole with the drilling bit An object of this invention is to provide a combined signal generator and time control mechanism therefor by means of which current from a.I direct current source such as dry batteries is converted by means of a vibrator-convertor into a low frequency alternating current having a frequency of the order of 8 to 10 cycles per sec.- ond, a square wave form, and a relatively high current value of the order of 6 amperes.

A further object of this invention is to lprovide a compact, rugged unit so constructed that the signal generated thereby will not be affected by the rotation of the bit or other vibrations due to drilling.

Other and m'ore detailed objects of the invention will be apparent from the following disclosure of the embodiment thereof illustrated in the attached drawings.

This invention resides substantially in the combination, construction, arrangement and relative location of parts, all as will be described in detail below. c

In the accompanying drawings,

Figure 1 is a vertical, central, cross-sectional view through the vibrator-convertor-portion of the device;

Figure 2 is a cross-sectional view taken on the line 2-2 of Figure 1;

Figure 3 is a cross-sectional view taken on the line 3-3 of Figure 1;

Figure 4 is an elevational view of another portion of the unit showing pole pieces in crosssection, which l unit portion is adapted to be Figure 7A is a side elevational view of the upper terminal element of the structure of Figure 4;

Figure 7B is asimilar-viewfrom a. right angle position with respect to Figure 7A;

Figure '7C is a top plan view of this element;

Figure 7D is a bottom plan view thereof;

Figure 8 is a vertical, central, cross-sectional view through the time control portion of the unit showing some parts in elevation, which unit portion is adapted to be mounted on the upper end of the unit portion of Figure 4:

Figure 9 is a cross-sectional view taken on the line 9-9 of Figure 8;

Figure 10 is a cross-sectional view taken on the line Ill- III of Figure 8;

Figure 11 is a cross-sectional view taken on the line II-II oi' Figure 8;

` Figure 11A shows the parts oi Figure 11 in switch open position;

Figure 12 is a cross-sectional view taken on the line |2--I2 of Figure 8;

Figure 12A is a cross-sectional view taken on the line IZA-IZA of Figure 8; and

Figure 13 is a circuit diagram of the electrical connections of the device. y

The function of the various parts of the device of this invention will be best understood after a detailed disclosure of the structure of which it is composed, and its description will, therefore be deferred until later.

Referring to Figures i, 2 and 3, the unit portion illustrated therein comprising the vibratormounted on the upper end of the unit portion of Figure 1;

Figure 4A is a side elevational detailed view of a pair of brackets forming part of the structure of Figure 4;

Figure 4B is a side elevational view of one of said brackets;

Figure 4C is a top plan view of these brackets shown in their relative assembled position;

Figure 5 is a cross-sectional view taken on the line 5-5 oLFigure 4;

Figure 6 is a cross-sectional view taken on the line 6--8 of Figure 4;

Figure 'l is a cross-sectional view taken on the line 'l-1 of Figure 4;

convertor includes a cylindrical housing I, preferably of metal, closed at the lower end, and of a size which will permit of its introduction into a bore hole, as for example an overall diameter of two inches. The housing I is attached to a nonmagnetlc structure 3 which is provided with a seat therefor, as shown. The element 3- is of brass or other non-magnetic material and serves as a mount for the bearing I2 of shaft I3 (see Fig. 3) and has a seat on its upper end for housing section 6 of non-magnetic material such as brass. The housing t serves as an enclosure or container for coil form 2 and winding I4, as clearly shown in Figure l. At 3' are a pair of magnetizable pole pieces which have the outline clearly shown in Figure 1. These pole pieces are mounted in slots in the non-m'agnetic element 3 as shown in Figure 3. The housing 6 is in fact, as shown in Figure 2, made up of two nearly semicircular halves which together with the magnetizible strips or bars 3' complete the circular housing.' The magnetizable strips 6' seat in corner notches in the pole pieces I', as clearly shown in Figure 1, and extend all the way to the top of the casing 6 of which they form a part, also as shownin Figure l. When the unit oi Figure 4 is mounted on the top or the housing 8 the magnetizable strips 8' will abut the pole pieces l5 of Figure 4. The upper portion of the structure 2 is tubular in form and provides a coil form for the magnetlzable winding I4. A magnetizable armature I is pivotally mounted at Il in the structure 3 by means-of ball bearings I2, from which it is insulated by means of the insulating sleeves I3. The supporting shaft Il is connected by a resilient pigtail I! to a terminal block 4, as shown in Figure 3, to which one end of the winding I4 is connected as well as a wire 3| to be described later. The other end of the winding I4 is connected to wire 5 which has a branch connection 32 for a purpose to be described later. As will be described later in connection with Figure 13, wire 5 extends to the battery source (not shown). Any type of battery case or container can be suspended or attached by any suitable means to the bottom of unit I (see Fig. l) as indic'ated by the dotted extension lines B. This case or container forms a housing for batteries I'I and 22 connected as shown in Figure 13 to wires 5, 5e, 5, 1 and 8. Mounted in the upper end of the magnet tube 2 is a copper ring 20 employed for the purpose of making the action of the magnet 2-I4 sluggish.

Mounted on the lower end of the armature I0 and in electrical contact therewith are a pair of spring arms each supporting one of a pair of contacts I8, the other of vwhich is mounted on an insulating block on the inner wall of the tube I. A xed contact of each contact pair I8 is connected by the wires 5 and 5b respectively to the current source as will be described in connection with Figure 13. Also mounted upon the armature I0 and in electrical contact therewith is another pair of spring arms carrying a contact of each of the pairs 2l. The other contact oi each pair is mounted upon a spring arm 2IA which is mounted upon the same insulating block which supports a iixed contact of the contact pairs I8. These blocks have adjusting screws 26 for placing the springs2I`A under tension by reason of the fact that their lower ends engage insulating stops near the bottom of tube I, as shown. The spring lingers 2 IA are connected by the Wires 'l and 8 respectively to the signal current source 22, as will be explained in connection with Figure 13. The lower end of the armature I0 has an aperture therethrough as shown, in which a frictional damping piston 25 is slidably mounted and yconnected to the spring fingers which support one contact of each of the contact pairs 2|. The tensioning of the spring fingers ZIA and the damping piston 25 serve to prevent bouncing or sharp"reactions of the armature by reason of the engagement and disengagement of the contacts of contact pairs 2 I. The upper end of the armature I0 oscillates on the shaft II withinthe tubular magnet core 2.

In Figures 4 to 7 inclusive is illustrated the next unit portion of the device. This unit portion comprises an attaching member forming an extension of the coil form 2 and the housing 6. This extension comprises a pair of members I5a and I5b made of some non-magnetic material such as brass. The pole pieces I5 are set between these two' members I 5* and I5 which are nearly semi-circular so as to form together as illustrated in Figure 5, a disc the parts of which can be secured together in any suitable manner.y The diameter ot this disc unit iszequal to the external diameter of the housing C and is provided with a pair of holes I51 by means of which the disc can be attached to the end of the coil iorm by means of screws. The disc unit is provided with another pair of holes I5 by means of which a pair of brackets S (see Figs. 4 and 4A to 4C) are mounted thereon. Thus the holes I5' and the brackets S will line up with the holes I5c and the brackets secured by screws therein. The upper ends of the brackets are attached by means of screws in the holes Iiif to a notched disc 6b (see Figs. 4 and 6), on which the upper portion of this part of the unit is mounted. Clamped between the brackets S by means of screws or bolts in the holes I5l are a pair of semi-circular permanent magnets I6 and 2l, the former oi which contacts the pole pieces I5. Set in radial slots in the non-magnetic disc 6b are a pair of magnetizable extensions 28 of the magnetizable member 28 shown in full `detail in Figures 7A to 7D. These extensions 28' contact the ends of the permanent magnet 21 so that the member 28 forms part of the magnetic circuit thereof. The member 28 is ring-like, as shown, with the integral extensions 28' extending in one direction and an extension 28" of reduced diameter extending in the opposite direction to receive an enclosing ring 28l which is sweated onto the member 28 and forms a continuation of the full diameter of the device and a seat for the attachment thereto of unit 9 as indicated by the unit 8 of Figure 8, as indicated by the broken lines 9 in Figure 4. A

As clearly shown in Figures 7 to 7C the interior of the member 28 is shaped to form a substantially rectangular enclosure in which a magnetizing winding 29 is mounted. The terminals of this winding are connected to the wires 3l and 32 respectively of Figure 1, and hence the winding 29 is in parallel with the winding Il (see Fig. 13). An armature 30 is pivotally mounted on one of the screws 33 which passes through one of the apertures Se by means of which the disc 6b is attached to the upper ends of the brackets S. The 45 Magnetizable member 28 has a radial slot at 28h in which the end of the armature oscillates and on which end a vertical extension 34 is attached. This extension is provided with a spring ringer 3B at its upper end.

Spring finger 36 extends upwardly into the unit portion illustrated in Figure 8 comprising a tubular housing 8 of any suitable material but preferably of metal and comprising a pair of telescoped tubes, as shown. This cylinder is closed at the 55 upper end as illustrated in Figure 8.: At this point it m'ay be well to note that the unit section of Figure 4 is placed on the upper end of the unit section of Figure 1, and the unit section of Figure 8 is placed on the upper end of the.unit sec- 60 tion of Figure 4. These parts are secured together in any suitable manner to form a single elongated structure of uniform external diameter and adapted to be lowered into a. bore hole.

Within the housing 3 are a spaced pair of sup` 65 ports 50 and 5I in which are journaled at the ends a pair of threaded shafts 4I and 42 on which are respectively mounted the internally threaded pinions 39 and I0. Likewise journaled between supports 50 and 5I is a long pinion 38 positioned between the threaded shafts Il' and l2 so as to mesh with the pinions 38 and I8, as is clear from Figure 9.

On the lower end of the gear 3l is a gear 31 positioned to be engaged by the spring iinger 38, and by a fixed pawl 3l which prevents any backdashing in the movement of this geen ,'Mounted on 4the support 5I is an insulating support 52 through which the threaded 'shafts 4l and 42 extend but theirv extensions have reduced Adiamet'ers as shown. Indeed these extensions pass through to the top of the instrument'as is clear from Figure 8. However, shaft 42 has an eni larged portion 63 just above the support 52 and mounted upon the insulating support 52. Thisy spring finger is connected to the wire 3 I as shown'. This spring finger has a contact on it adapted to cooperate with a fixed` contact 58 m'ounted on the support 52, which is connected by the wire 59, see Figures 8 and i3, to another switch to be described.

\ Mounted in the housing 8 is another support 60, preferably of insulating material above which an escape mechanism is mounted. This mechanism includes a pair of varms 6I and62 pivotally mounted on the support 63. These arms are united at their free ends by a tension spring 64. As will be seen from Figure 8, the arms 6I and 62 have lateral extensions at different levels for cooperation with the cams l815 and 68 respectively. These cams are mounted upon the shaft 4I and are rotated by it. Rotatably mounted upon the shaft above these cams is a pawl 81 which is connected to the shaft by means'of a spring encircling the shaft. The pawl 61 cooperates with the oppositely facing shoulders 83 and 10 on the upper faces of the arms 6I and 62 respectively. In Figure 12A, shoulder 68 faces downwardly and shoulder faces upwardly. Secured to the hub 1l of the paw] 61 is an eccentric cam' 12 upon which a crank arm i3 is mounted. This crank arm is pivotally connected at 14 to a switch arm 15 pivotally mounted on the support 60 at 16. This switch arm is provided at the end with a contact which cooperates with a fixed contact 11 connected to the wire 58. A switch arm 15 is grounded on the housing if it is of metal by means of a spring contact 18.

The circuit connections have been indicated briefly in the previous description. but they are clearly shown in Figure 13. ri'he operating battery'Il for the windings I4 and 29 comprises a pair of sections having a center connection to the wire 5 so that these magnets can be alternately energized in opposite directions as the armature I0 oscillates to make and break circuits from these batteries at the contacts I8. Thus in v,the position of the parts shown current will now from the left hand portion of battery I1 through wire 5, ythrough coil I4, pigtail I8, armature I8, contacts i8 and wire 5EL back to the battery. This will energize the winding I4 in view of its polarization by the permanent magnet I6 so as to cause the armature to move from the position shown in counterclockwise direction to its other position where the right hand contacts I8 make. Those skilled in the art can readily trace the circuit thus made to effect reverse energization of the winding I4 through the other portion of the battery I1 to cause the amature I0 to move back to the position shown in Figure 13. The short circuited copper ring illustrated in Figure 1 will delay the building up of the magnetic eld of the magnet I4 to cause the desired slow oscillation of the armature III and the generation of a low frequency current. as will now be described. It is, of course. apparent that the inertia of the oscillating armaturevlll can be adjusted to contribute to the de- 5 sired speed of operation.

As previously stated the winding 29 is in parallel with the winding I4 so that it toois simultaneously energized in alternate directions which due to its polarization by the permanent magnet 21 will cause an oscillation of the armature 30 at the same frequency, thereby driving the mechanism of the unit portion of Figure 8 through thev spring nger 36 in a manner shortly to be described.

The oscillation of the armature I0 will con- `vert the direct current from the battery source 22 into a lowfrequency alternating current of substantiallyy square wave form by reason of the f fact that circuits are alternately completed as 20 follows: Current flows from ground through the right hand portion of the battery 22, right hand contacts 2 I., armature I0, pigtail I9, wire 3|, and .switches 23 and 24 when closed to ground. When the armature shifts to its other position this portiony of the battery 22 through the leftl hand pair of contacts 2|. The alternate making and breaking of the contact pairs 2|4 will produce an alternating current of squarewave form of a frequency corresponding to the frequency of oscillation of the armature I 8 in a manner well known to those skilled in the art.

This signal current, however, is not generated except when switches 23 and 24 are closed. The mechanical mechanism for' operating these switches will now be described. As the device is ready to be loaded into the bore hole the circuit from the battery I1 tothe winding I4 is. closed in any suitable manner, as by means of a switch, not shown, so as to set the armature I8 in oscillation. Winding 29 being in parallel with the Winding i4 is intermittently energized at the same time, causing armature 30 to oscillate back and forth on its pivot support 33. Thus the spring finger 36 moves back and forth to cause intermittent rotation of the ratchet wheel 31 and rotation with it of the elongated gear 38. The rotation of gear 38 causes rotation of the gears 39 and 40 on the threaded shafts 4I and 42. Since the 50 gears 39 and 40 are threadedly mounted on these shafts they simply rotate and slowly travel up the shafts 4| and 42. `Their rate of travel can be predetermined for any speed of oscillation of the armature I0 and hence the armature 30 by the proper selection of ratio of gear 38 to the gears 39 and 40. Likewise the speed of vertical movement of the gears 39 and 40 on the threaded shafts 4I and 42 can be predetermined by the proper selection ofthread sizes. When gear 48 reaches y theend of the thread at the upper end of shaft 42,

continued rotation of gear 38, and hence gear 48,

will cause rotation of threaded shaft 42 because the threaded gear 40 jams on that shaft.

Wher the shaft 42 rotates from the position shown in Figure 11A to about the position shown in Figure 11, the notched portion 53 thereof will release the pawl of the'spring pressed trigger 55 so that it moves to the position shown in Figure 11, and m'oves the arm 56 in a counter-clockwise direction to close switch 23 as shown inFigure 11.

These parts are all proportioned so that the operator will have suilicie'nt time to drop the generator in the bore hole or the drill bit with the lgenerator attached to the bottom of the bore hole.

Threaded gear 38 reaches the end of the threads same circuit will be completed from the other 7 on the shaft 4| at about the same time so that it jams thereon and starts rotation of the shaft 4 l and hence the cams 65 and 66. These cams respectively engage the lateral shoulders on the pivotally supported arms 6i and 62 so as to alternately move them outwardly. Assuming that the parts are in the position shown in Figure 12, when cam 65 moves arm 6l outwardly, Figure 12A, its shoulder 69 will disengage the pawl 61, permitting spring 68 which is loaded to snap the pawl around through an angle of approximately 180 degrees until the pawl engages the shoulder 10 on the arm 62. This rotation of pawl 61 causes rotation of the eccentric 12 and the movement of crank arm 13, so as to open or close switch 24,/ depending upon the position it is in. It is preferred that at the start of operations switch 24 be in closed position, as shown in Figure 12A, so that the first movement of the eccentric 12 will open the switch 24. Thus when switch 23 closes, switch 24 already being closed, the alternating current output of the signal generator will be applied to the drill pipe through the connection |00, Figure 13, which is grounded on the drill pipe, as indicated. Thus the alternating current output of the generator will be applied at one terminal to the drill pipe and at the other terminal to ground, that is at the battery 22. Thus the first movement of the crank 13 will open the switch, disconnecting the signal generator from the drill pipe. From an exact mechanical viewpoint it is noted that the connection is made through the grounding spring 18, Figure 12A, on to the metal housing 9, which in turnis connected to the drill pipe.

Shaft 4l is now rotating continuously, and hence when cam 66 moves to proper position pivoted arm B2 will move outwardly to disengage its shoulder with the pawl 61. It will then rotate back to the position shown in Figure 12, closing switch 24 which has opened in the meantime, as

previously explained. Thus by these operationsV switch 24 which is the intermittent switch, intermittently connects the generator. to the drill pipe, and disconnects it therefrom. The relative length o f the on and off periods can easily be adjusted by changing the relative positions of the high pointsv on the cams 65 'and 66. It will be noted that the continued rotation of shaft 4l keeps loading spring 68 to take up the unloading due to the step-by-step movement of the pawl 61.

Thus by means of the time control mechanism disclosed the operation of the switches for connecting and disconnecting the signal generator to and from the drill pipe is not initiated until about the time the device reaches the bottom of the bore hole. When 'the'signal generator circuits are put into operation they are operated intermittently. Thus the life of the battery 22 is maintained at a maximum since it is not ever on a continuous short circuit. Trigger 55 must be reset manually since once it is operated by being released from the member 53, it remains in the position shown in Figure 11 to hold switch 23 closed. It will be apparent that the gears 39 and 40 may be relatively positioned with respect to each other on their threaded shafts so as to prearrange the relative times of arrival thereof at the ends of the threads on the shafts 4I and 42. Mechanical arrangements can easily be made to permit of the disengagement of gear 39 with the gears 39 and 40 to permit of this relative adjustment.

As those skilled in the art will clearly appreciate, the complete device includes the three units of Figures 1, 4 and 8 and a battery case or con- 8 tainer (not shown) below the unit shown in Filure 1, securedtogether in end to end relation in any suitable manner and enclosed within a suitable fluidtight housing (not shown) adapted tn be lowered into a bore hole. i For example. a length of pipe closed at the ends by threaded caps would be suitable to form a fiuidtight housing for this purpose. l

From the above description it will be apparent to those skilled in the art that the subiect matter. of this invention is capable of considerable variation, and I do not, therefore, desire to be strictly limited to the disclosure as given herein, but rather by the scope of the claims grantedl me.

What is claimed is:

1. In ay device of the type described the combination comprising a housing, a vibrator motor mounted in said housing, means actuated by said motor for converting a direct current into an alternating current, a signal output circuit connected to said last means, a pair of switches connected in series in said circuit, a second vibrator motor intermittently operated by said first motor. and driving means actuated by said second motor for closing one of said switches after a predetermined time interval, and for intermittently actuating the other of said switches.

2r In the combination of claim 1, said driving means including a pair of threaded shafts and rotatable nuts mounted on said shafts, said nuts causing rotation of said shafts when they reach the ends of the threads thereof, said switches being respectively actuated by said shafts.

3. A signal transmitter comprising a signal said ratchet means, a pair of rotatably mountedthreaded shafts adjacent said gear, a pair of gears threadedly mounted on said shafts respectively and meshing with said elongated gear, spring biased means released by one of saidshafts for closing one of said switches when said shaft is rotated, and means operated by the other of said shafts when it is rotated for intermittently closing the other of said switches, said threaded gears moving longitudinally of said shafts until they reach the end of the threads thereof whereupon continued rotation thereof causes rotation of said shafts.

WILLIAM R. FLATFORD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,400,126 Wotton Dec. 13, 1921 1,624,476 Cummings Apr. 12, 1927 1,811,858 Miller June 30, 1931 1,991,658 Clark Feb. 19, 1935 2,012,456 Kothny Aug. 27, 1935 2,167,630 Bazzani et al Aug. 1, 1939 2,295,738 Gillbersh Sept. 15, 1942 2,338,028 Doll Dec. 28, 1943 2,357,177 Doll Aug. 29, 1944 

